Low floor vehicles, such as buses for example, utilize electric wheel drives with trailing arm suspensions. Each wheel includes a spindle and a wheel drive shaft that rotates relative to the spindle about a lateral axis of rotation. A traditional configuration utilizes an electric motor that has a motor output shaft that extends perpendicular to the lateral axis of rotation. A right angle, multiple gear reduction box is used to transmit driving power from the motor output shaft to the wheel drive shaft. An oil pump is also typically attached to the gear reduction box to provide sufficient lubrication.
A traditional suspension configuration utilizes a trailing arm that extends underneath the electric motor along a longitudinally extending length of the electric motor. The suspension arm includes a pivot end that is attached to a vehicle structure and an attachment end that is fixed to the gear reduction box. The electric motor is mounted to the vehicle structure with brackets.
One disadvantage with this traditional configuration is the amount of packaging space required for the electric motor, gear reduction box, oil pump, etc., which reduces space available for other components. Another disadvantage is the weight and cost of these various components.
Thus, there is a need for a more compact, reduced weight wheel drive assembly that overcomes the deficiencies in the prior art discussed above.